Impacts of Climate Change on Hydrologic Processes in the Colorado River Basin

The clear evidence of human-induced hydroclimatic shifts in the western U.S., and especially within the Colorado River Basin (CRB), has motivated the research community to pursue reliable estimates of future climate change impacts on hydrological processes. Although the large body of literature in this field shows consensus on the future drying of the CRB, there are large uncertainties in the magnitude of hydrologic changes because of differences in experimental approaches. Hence, this work focuses on the effects of methodological choices, in particular those related to hydrologic modeling, on the portrayal of climate change impacts at three catchments located in the headwaters of the CRB.A commentary on the current development of complex process-based hydrologic models is first presented. It is argued that the relatively poor performance of such models may occur due to restrictions on their ability to refine their portrayal of physical processes, and improving hydrological models requires integrating the strengths of prior knowledge of hydrologic processes with the strengths of data driven inference. An assessment of the effects of hydrologic model choice and parameter calibration on projected hydrologic changes follows. Here, it is demonstrated that the subjective selection of model structures may introduce large uncertainties to hydrologic projections. Based on this, the third part of this study compares the effects of hydrologic model choice and parameter estimation strategies on projected climate change impacts. The main finding here is that the choice of parameter estimation methods can provide similar or larger uncertainties in some hydrologic processes when compared to uncertainties coming from model choice. The fourth component of this study evaluates the effects of regional climate model (RCM) configuration and forcing scaling on projected hydrologic changes. The results illustrate the implications of RCM configuration on projected changes of the water cycle, and provide an integrated view of the interplay between forcings and hydrologic model structures in the portrayal of climate change impacts. Finally, a commentary on the main results of this study and possible ways to move forward is provided. It is asserted that a greater role of expert knowledge is required to improve model selection and parameter estimation, and also for incorporating non-stationarity in climate change impact studies

Key Success Factors and Barriers for Small Businesses: Comparative Analysis

AbstractThis paper analyses the current situation of small businesses, their outlook and their problems in Europe and in Russia. The number of small businesses opened, legislative system, number of self-employed without employees, influence of bureaucratic system on small business's life, unemployment and corruption are considered in this study. The object of this paper is understanding what can modify the life of small companies. Thus the analysis of every factor is useful to understand how the economy could change, what is correct and what resolutions make the life of small businesses better. The analysis is made using data from Eurostat, Rosstat, and Fedstat (an OECD institutional website), studying how values of indicators have changed during recent years. The results clearly show that the development of small companies is correlated with the development of good institutions, a sane community and trust and optimism in economy and small business sector

Nutrient resorption in dominant species of forests in the 'Espinal Mesopotámico' (Argentina)

Se estudió durante dos años (2009 y 2010) la retranslocación de nutrientes en especies dominantes de bosques correspondientes a una secuencia sucesional del Espinal Mesopotámico. El objetivo fue comparar la retranslocación de nutrientes (nitrógeno, fósforo, potasio, calcio, magnesio y azufre) entre especies de familias fabáceas (Acacia caven, Prosopis affinis y Prosopis nigra; con capacidad de fijar biológicamente el nitrógeno atmosférico) y celtidáceas (Celtis tala, sin capacidad de fijar biológicamente el nitrógeno atmosférico). Se analizaron químicamente las muestras de hojas maduras (recolectadas en primavera) y senescentes (recolectadas en otoño) para determinar la concentración de nutrientes y luego se calcularon los índices de retranslocación (Rc1 y Rc2). Se determinó que la mayor retranslocación del nitrógeno estuvo asociada la imposibilidad de fijar biológicamente el nitrógeno atmosférico, observándose que ambos índices denotaron una máxima retranslocación de nitrógeno en C. tala y mínima en A. caven. Contrariamente, los demás elementos (P, K, Ca, Mg y S) mostraron diferencias en la retranslocación en uno de los índices utilizados, indicando mayor resorción en fabáceas respecto a celtidácea, asociado a una mayor demanda foliar de estos elementos.The resorption of nutrients of dominant species in a successional sequence of forests of the Argentinean Mesopotamian Espinal was studied for two years (2009-2010). The aim was to compare nutrient resorption (nitrogen, phosphorus, potassium, calcium, magnesium and sulphur) among species of the Fabaceae (Acacia caven, Prosopis affinis and Prosopis nigra with the capacity of biologically fixing the atmospheric nitrogen) and Celtidacea families (Celtis tala, without the capacity of biologically fixing the atmospheric nitrogen). Samples of mature leaves (collected in spring) and senescent leaves (collected in autumn) were chemically analyzed to determine nutrient concentration; afterwards, resorption rates were calculated (Rc7 and Rc2). It was found that the higher nitrogen resorption was associated with the inability of biologically fixing the atmospheric nitrogen, having both indexes a maximum nitrogen resorption in C. tala and a minimum in A. caven. On the contrary, the other elements (P, K, Ca, Mg and S) showed resorption differences in one of the indexes used, indicating a higher resorption in Fabaceae in contrast with Celtidaceae, associated with a higher foliar demand of these elements.Fil: Mendoza, Carlos A.. Universidad Autónoma de Entre Ríos. Facultad de Ciencia y Tecnología; ArgentinaFil: Turrión, M. Belén. Universidad de Valladolid; EspañaFil: Aceñolaza, Pablo Gilberto. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina. Universidad Autónoma de Entre Ríos. Facultad de Ciencia y Tecnología; ArgentinaFil: Gallardo, Juan F.. Consejo Superior de Investigaciones Cientificas; EspañaFil: Pando, Valentín. Universidad de Valladolid; Españ

La centralita FVCel como recurso para la difusión de la energía fotovoltaica en la ciudad de Orán

El suministro eléctrico de la ciudad Orán proviene totalmente de la Red. El uso de las energías renovables en la zona urbana es casi nulo, solo se utilizan microsistemas fotovoltaicos en la zona rural. Con el propósito de iniciar acciones de difusión sobre el uso de fuentes alternativas, como el sol, docentes universitarios realizan el montaje de la Centralita FVCel en el predio de la sede. Se trata de una Estación FV Off Grid destinada a la carga de celulares, de fácil acceso y disponible para toda la comunidad universitaria. Durante 2017, fue usada como recurso indispensable para la difusión de la energía fotovoltaica en instituciones educativas del nivel Primario, Secundario y Terciario y la comunidad de Orán. A través de jornadas, charlas, visitas guiadas, muestras interactivas y ferias se procuró dar a conocer fuentes alternativas y generar conciencia sobre su disponibilidad y conveniencia de uso.The electricity supply of the city of Orán comes entirely from the Network. The use of renewable energies in the urban area is almost nil, only photovoltaic microsystems are used in the rural area. With the purpose of initiating dissemination actions on the use of alternative sources, such as the sun, university professors carry out the assembly of the Centralita FVCel on the headquarters premises. It is an Off Grid FV Station for cell phone charging, easily accessible and available to the entire university community. During 2017, it was used as an indispensable resource for the diffusion of photovoltaic energy in educational institutions of the Primary, Secondary and Tertiary levels and the community of Oran. Through conferences, lectures, guided tours, interactive exhibitions and fairs, an effort was made to publicize alternative sources and raise awareness about their availability and convenience of use.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Evaluación de la aplicación de agua de mar para mejorar el CBR de la subrasante afirmada

The main human settlements in Peru lack paved roads or affirmed carriage trails for the continuous or safe movement of vehicles. In this work, the evaluation of the application of seawater in the affirmed subgrade is exposed. Laboratory tests have been carried out, managing to see that the most important indicator of the resistance of the tracks helps in a significant way to improve the California Bearing Ratio (CBR). The results using with drinking water are 64.30%, 78.30%, and 95.20% of CBR and with seawater much higher CBR values of 99.20%, 90.90%, and 109.10%, for which an improvement of 34.90% was obtained and with this it is concluded that the addition of seawater significantly increases the California Bearing Ratio (CBR) of the affirmed subgrade. Keywords: Seawater, affirmed subgrade, CBR, road infrastructure. References [1]D. Flórez, and B. Bernabé, “El agua de mar en la alimentación y la terapéutica,” Sociedad Española de hidrología médica, vol. 30, no. 1, pp. 37-55, 2014. [2]J. Domenech, “Control de la calidad del agua”, Offarm, vol. 21, no. 10, pp. 138-146, 2002. [3]M. Bernardo et al., “Valoración terapéutica del agua de mar en modelos experimentales como terapia complementaria en anemia”, Medica UIS, vol 27, no. 3, pp. 9-18, 2014. [4]A. Fernández, “El agua: un recurso esencial”, Química Viva, vol 11, no. 3, pp. 147-170, 2012. [5]J. Miranda and D. Negrete, “Estabilización de suelos cohesivos con el uso de cloruro de calcio , Pontifica Universidad Católica del Ecuador, Quito, 2011. [6]D. Pumaricra, “Cloruro de magnesio como aditivo en el tratamiento de las propiedades físico mecánicas de la superficie de rodadura en carreteras no pavimentadas”, Pontifica Universidad Católica del Ecuador, Quito. (2019). [7]Ministerio de Transportes y Comunicaciones, “Manual de Carreteras: Suelos, Geología, Geotecnia y Pavimento – Sección Suelos y Pavimentos”, Lima, 2014. [8]C. Gutiérrez, “Estabilización química de carreteras no pavimentadas en el Perú y ventajas comparativas del cloruro de magnesio (bischofita) frente al cloruro de calcio”, Universidad Ricardo Palma, Lima, Perú, 2010. [9]C. Caruajulca, “Influencia del aditivo cloruro de sodio como estabilizante de la subrasante de la carretera tramo cruce el porongo – aeropuerto – Cajamarca”, Universidad Nacional de Cajamarca, Cajamarca, Perú, 2018. [10]C. Chavarry, R. Figueroa and R. Reynaga, “Estabilización química de capas granulares con cloruro de calcio para vías no pavimentadas”, Polo del conocimiento, vol. 5, no. 6, pp. 40-69, 2020. [11]P. Garnica and A. Pérez, “Estabilización de suelos con cloruro de sodio para su uso en las vías terrestres”, Publicación técnica, México, 2002. [12]H. Llerena, “Mejoramiento de una base superficial con cloruro de magnesio hexahidratado”, Universidad Nacional de San Agustín de Arequipa, Arequipa, Perú, 2015. [13]S. Cuadros, “Mejoramiento de las propiedades físico–mecánicas de la subrasante en una vía afirmada de  departamental de la región Junín mediantela estabilización química con óxido de calcio – 2016”, Universidad Peruana los Andes, Huancayo, Perú, 2017. [14]J. Rivera, and R. Mejía, “Estabilización química de suelos - Materiales convencionales y activados alcalinamente”, Informador Técnico, vol. 84, no. 2, pp. 202-226, 2020. [15]G. Thenoux, and S. Vera, “Evaluación de la efectividad del cloruro de magnesio hexahidratado (bischofita) como estabilizador químico de capas de rodadura granulares”, in Consejos Superior de Investigaciones Científicas, p. 1. , 2002.Resumen: Los principales asentamientos humanos en el Perú, carecen de vías pavimentadas o trochas carrozables afirmadas para el desplazamiento de los vehículos de manera continua o segura. En este trabajo se expone la evaluación de la aplicación del agua de mar en la subrasante afirmada. Se han realizado ensayos de laboratorio, logrando ver que si ayuda de manera significativa a mejorar el California Bearing Ratio (CBR) el indicar más importante de la resistencia de las vias. Los resultados utilizando con agua potable son de 64,30%, 78,30% y 95,20% de CBR y con agua de mar valores de CBR mucho más altos de 99,20%, 90,90% y 109,10%, por lo que se obtuvo una mejoría de 34,90% y con ello se concluye que la adición de agua de mar aumenta significativamente el California Bearing Ratio (CBR) de la subrasante afirmada. Palabras Clave: Agua de mar, subrasante afirmada, CBR, infraestructura vial. Referencias [1]D. Flórez, y B. Bernabé, “El agua de mar en la alimentación y la terapéutica,” Sociedad Española de hidrología médica, vol. 30, no. 1, pp. 37-55, 2014. [2]J. Domenech, “Control de la calidad del agua”, Offarm, vol. 21, no. 10, pp. 138-146, 2002. [3]M. Bernardo et al., “Valoración terapéutica del agua de mar en modelos experimentales como terapia complementaria en anemia”, Medica UIS, vol 27, no. 3, pp. 9-18, 2014. [4]A. Fernández, “El agua: un recurso esencial”, Química Viva, vol 11, no. 3, pp. 147-170, 2012. [5]J. Miranda y D. Negrete, “Estabilización de suelos cohesivos con el uso de cloruro de calcio , Pontifica Universidad Católica del Ecuador, Quito, 2011. [6]D. Pumaricra, “Cloruro de magnesio como aditivo en el tratamiento de las propiedades físico mecánicas de la superficie de rodadura en carreteras no pavimentadas”, Pontifica Universidad Católica del Ecuador, Quito. (2019). [7]Ministerio de Transportes y Comunicaciones, “Manual de Carreteras: Suelos, Geología, Geotecnia y Pavimento – Sección Suelos y Pavimentos”, Lima, 2014. [8]C. Gutiérrez, “Estabilización química de carreteras no pavimentadas en el Perú y ventajas comparativas del cloruro de magnesio (bischofita) frente al cloruro de calcio”, Universidad Ricardo Palma, Lima, Perú, 2010. [9]C. Caruajulca, “Influencia del aditivo cloruro de sodio como estabilizante de la subrasante de la carretera tramo cruce el porongo – aeropuerto – Cajamarca”, Universidad Nacional de Cajamarca, Cajamarca, Perú, 2018. [10]C. Chavarry, R. Figueroa y R. Reynaga, “Estabilización química de capas granulares con cloruro de calcio para vías no pavimentadas”, Polo del conocimiento, vol. 5, no. 6, pp. 40-69, 2020. [11]P. Garnica y A. Pérez, “Estabilización de suelos con cloruro de sodio para su uso en las vías terrestres”, Publicación técnica, México, 2002. [12]H. Llerena, “Mejoramiento de una base superficial con cloruro de magnesio hexahidratado”, Universidad Nacional de San Agustín de Arequipa, Arequipa, Perú, 2015. [13]S. Cuadros, “Mejoramiento de las propiedades físico–mecánicas de la subrasante en una vía afirmada de  departamental de la región Junín mediantela estabilización química con óxido de calcio – 2016”, Universidad Peruana los Andes, Huancayo, Perú, 2017. [14]J. Rivera, y R. Mejía, “Estabilización química de suelos - Materiales convencionales y activados alcalinamente”, Informador Técnico, vol. 84, no. 2, pp. 202-226, 2020. [15]G. Thenoux, y S. Vera, “Evaluación de la efectividad del cloruro de magnesio hexahidratado (bischofita) como estabilizador químico de capas de rodadura granulares”, in Consejos Superior de Investigaciones Científicas, p. 1. , 2002

Energy feeding strategies to shorten the postpartum anoestrous in grazing dairy cows

A prolonged postpartum anoestrus (PPA) is related to a low reproductive efficiency in dairy farms, independently of the calving pattern or feeding system. Postpartum luteal activity resumption is coincident with the onset of lactation when the cow is in negative energy balance, which depending on its magnitude could alter the hypothalamus – pituitary – ovary axis of the animal and prolong the PAA. In this article, some results from experiments that manipulated nutrition as a strategy to shorten the PPA, with emphasis in grazing systems, are briefly reviewed. Available information suggests that manipulation of the level and source of dietary energy are promising tools to reduce the length of the PPA in grazing dairy cows and increase the reproductive efficiency in dairy farms

The CAMELS-CL dataset: catchment attributes and meteorology for large sample studies – Chile dataset

We introduce the first catchment dataset for large sample studies in Chile. This dataset includes 516 catchments; it covers particularly wide latitude (17.8 to 55.0∘ S) and elevation (0 to 6993 m a.s.l.) ranges, and it relies on multiple data sources (including ground data, remote-sensed products and reanalyses) to characterise the hydroclimatic conditions and landscape of a region where in situ measurements are scarce. For each catchment, the dataset provides boundaries, daily streamflow records and basin-averaged daily time series of precipitation (from one national and three global datasets), maximum, minimum and mean temperatures, potential evapotranspiration (PET; from two datasets), and snow water equivalent. We calculated hydro-climatological indices using these time series, and leveraged diverse data sources to extract topographic, geological and land cover features. Relying on publicly available reservoirs and water rights data for the country, we estimated the degree of anthropic intervention within the catchments. To facilitate the use of this dataset and promote common standards in large sample studies, we computed most catchment attributes introduced by Addor et al. (2017) in their Catchment Attributes and MEteorology for Large-sample Studies (CAMELS) dataset, and added several others. We used the dataset presented here (named CAMELS-CL) to characterise regional variations in hydroclimatic conditions over Chile and to explore how basin behaviour is influenced by catchment attributes and water extractions. Further, CAMELS-CL enabled us to analyse biases and uncertainties in basin-wide precipitation and PET. The characterisation of catchment water balances revealed large discrepancies between precipitation products in arid regions and a systematic precipitation underestimation in headwater mountain catchments (high elevations and steep slopes) over humid regions. We evaluated PET products based on ground data and found a fairly good performance of both products in humid regions (r>0.91) and lower correlation (r<0.76) in hyper-arid regions. Further, the satellite-based PET showed a consistent overestimation of observation-based PET. Finally, we explored local anomalies in catchment response by analysing the relationship between hydrological signatures and an attribute characterising the level of anthropic interventions. We showed that larger anthropic interventions are correlated with lower than normal annual flows, runoff ratios, elasticity of runoff with respect to precipitation, and flashiness of runoff, especially in arid catchments. CAMELS-CL provides unprecedented information on catchments in a region largely underrepresented in large sample studies. This effort is part of an international initiative to create multi-national large sample datasets freely available for the community. CAMELS-CL can be visualised from http://camels.cr2.cl and downloaded from https://doi.pangaea.de/10.1594/PANGAEA.894885

Existencia de solución de un problema de contorno aplicando el metodo de super y sub-soluciones

En el presente artículo se muestra un resultado de existencia de solución para un problema de contorno usando el método de super y sub-soluciones. Bajo condiciones apropiadas, se prueba la existencia de solución de un problema periódico utilizando el teorema de punto fijo de Schauder

Shaping point- and mirror-symmetric proto-planetary nebulae by the orbital motion of the central binary system

We present 3D hydrodynamical simulations of a jet launched from the secondary star of a binary system inside a proto-planetary nebula. The secondary star moves around the primary in a close eccentric orbit. From the gasdynamic simulations we compute synthetic [NII] 6583 emission maps. Different jet axis inclinations with respect to the orbital plane, as well as different orientations of the flow with respect to the observer are considered. For some parameter combinations, we obtain structures that show point- or mirror-symmetric morphologies depending on the orientation of the flow with respect to the observer. Furthermore, our models can explain some of the emission distribution asymmetries that are summarized in the classification given by Soker & hadar (2002).Comment: 15 pages, 3 figures, 2 tables, Accepted in Apj Letter